Technical overview and clinical outcomes of transabdominal strategies to eliminate or neutralize staple-line intersection during low anterior resection: a systematic review

Abstract Aim To systematically classify and describe transabdominal surgical techniques designed to eliminate or neutralize staple-line intersection during low anterior resection (LAR), and to summarize their reported clinical outcomes. Methods A systematic review was conducted according to PRISMA guidelines and registered in PROSPERO (CRD420261368367). Major databases were searched for studies describing transabdominal techniques aimed at eliminating or neutralizing staple-line intersection in colorectal anastomosis during LAR. Both modified double-stapling techniques (mDST) and abdominal single-stapled techniques (aSST) were included. Outcomes of interest included anastomotic leak (AL), use of protective stoma, and perioperative variables. Reported outcomes were descriptively summarized, and exploratory aggregated analyses were performed when appropriate. Results Seventeen studies (998 patients) were included. Ten studies (529 patients) evaluated mDST (suture-based: n = 192; invagination-based: n = 337), while seven studies (469 patients) assessed aSST. Reported AL rates remained low across both mDST subgroups (3.1% suture-based vs 3.9% invagination-based), with an aggregated rate of 3.6%. The aSST group showed a leak rate of 6.0%. Protective stomas were used in 6.2% of mDST and 33.1% of aSST. Neoadjuvant therapy was used in 20.7% of aSST and 11.9% of mDST. Considerable heterogeneity in study design, technique, and outcome reporting was observed. Conclusions Transabdominal techniques that eliminate or neutralize staple-line intersection appear feasible and associated with low anastomotic leak rates. Modified DST techniques appear technically feasible and have been associated with low reported leak rates. However, owing to the heterogeneity of the available evidence, comparative findings should be considered exploratory.